tailieunhanh - Báo cáo khoa học: The crystal structure of NlpI A prokaryotic tetratricopeptide repeat protein with a globular fold

There are several different families of repeat proteins. In each, a distinct structural motif is repeated in tandem to generate an elongated structure. The nonglobular, extended structures that result are particularly well suited to present a large surface area and to function as interaction domains. Many repeat proteins have been demonstrated experimentally to fold and function as independent domains. | iFEBS Journal The crystal structure of NlpI A prokaryotic tetratricopeptide repeat protein with a globular fold Christopher G. M. Wilson1 Tommi Kajander1 and Lynne Regan1 2 1 Department of Molecular Biophysics and Biochemistry Yale University New Haven CT USA 2 Department of Chemistry Yale University New Haven CT USA Keywords crystal structure NlpI lipoprotein tetratricopeptide TPR Correspondence L. Regan Yale University PO Box 208114 New Haven CT 06520-8114 USA Fax 1 203432 5767 Tel 1 203432 5566 E-mail Received 7 September 2004 revised 19 September 2004 accepted 19 September 2004 doi There are several different families of repeat proteins. In each a distinct structural motif is repeated in tandem to generate an elongated structure. The nonglobular extended structures that result are particularly well suited to present a large surface area and to function as interaction domains. Many repeat proteins have been demonstrated experimentally to fold and function as independent domains. In tetratricopeptide TPR repeats the repeat unit is a helix-turn-helix motif. The majority of TPR motifs occur as three to over 12 tandem repeats in different proteins. The majority of TPR structures in the Protein Data Bank are of isolated domains. Here we present the high-resolution structure of NlpI the first structure of a complete TPR-containing protein. We show that in this instance the TPR motifs do not fold and function as an independent domain but are fully integrated into the three-dimensional structure of a globular protein. The NlpI structure is also the first TPR structure from a prokaryote. It is of particular interest because it is a membrane-associated protein and mutations in it alter septation and virulence. Repeat proteins in general and tetratricopeptide repeats TPRs in particular have recently attracted interest from the perspectives of structure function folding and design 1-6 . The TPR was first identified .